With the rapid popularity of user equipment (UE), such as mobile phone, the user equipment is playing a more and more important role in people's life. In addition to the communication function of UE, other functions in UE are also utilized generally, for example, UE may be used to access a wireless local network (WLAN). Further, to facilitate the communication link, data exchange and the like between UE and other devices, interfaces, such as inferred, blue tooth, and USE, etc, have gradually become standard configurations of UE. Especially, the blue tooth earphone is being applied generally. WLAN system and blue tooth system both operate at the ISM (Industry Science Medicine) frequency bands. For example, the frequency band 2400 MHz-2483.5 MHz, which is one of the internationally utilized ISM frequency bands, is also one of most often used ISM frequency bands.
In the case that the frequency band on which the communication between a UE and a base station is based is close to the frequency band on which the communication between a UE and other devices is based or is multiples of the latter frequency band, the two communications may interference with each other. For example, the advanced long term evolution (LTE) system among wireless communication systems is one of the super 3G systems (Beyond IMT-2000). According to the LTE series standards [36.101], LTE system may operate at several frequency bands. In these LTE frequency bands, some frequency bands, such as the frequency band 40, i.e. 2300 MHz-2400 MHz for deploying LTE time division duplex (TDD) system and the frequency band 7, i.e. uplink 2500 MHz-2570 MHz and downlink 2620 MHz-2670 MHz, for deploying LTE frequency division duplex (FDD) system, are adjacent to the ISM frequency bands. Therefore, if a LTE UE works at the above frequency bands while the WLAN system or blue tooth system on the UE is activated, the LTE system and the ISM system (WLAN system, blue tooth system or the like) of the UE that work at the adjacent frequency bands interfere with each other due to the leakage of the adjacent frequency bands, or even face a communication failure due to high error rate.
A conventional method of solving the above issue is to utilize transmission filters of higher performance in both the transmitting end, communicating with the base station, on the UE (e.g. The LTE system on the UE) and the transmitting end, communicating with other devices, on the UE (e.g. The ISM system on the UE), so as to reduce the leakage of the adjacent frequency bands as much as possible. The disadvantage of such method is that the cost of the UE may be increased significantly.